Rear shock length question

rbair1

rbair1

New Member
Joined
Feb 4, 2019
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Location
Ohio
Hello all,
I'm currently rebuilding my 1999 TJ down to the last bolt driven by the need for a new frame and replacing the torque boxes in the tub.

I installed clayton offroad resr shock relocation brackets on the new to me dana 44 because it was missing any shock bracket at all. I have 3 inch lift springs and installed ranco rs5000 shocks for a 2-3 inch lift. When I installed the rear shocks, I had to put weight on the rear frame to get the springs to compress about. 5 inches to be able to get the shocks to bolt up. So now, at neutral state, the shocks are fully extended and there is no more uptravel... in fact springs are slightly compressed.

Now there is no tub on the frame yet or gas tank which would help to compress the rear, but I do not recall this when I took the Originals off.....

Is this typical? Is it bad to stroke oit the shocks...how much additional travel should the shocks have when at a neutral state? Do I need to buy longer shocks like the rs5000 for 4 to 5 inches of lift?

Thanks in advance for the advice.
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If you remove the rear springs and let the frame rest on the axle, that will give you the minimum length for your shock. If your shock is too long fully compressed, you will have to add bump stop extensions. Its recommended to leave 3/8"-1/2" of shock shaft showing at full compression. For the test to work properly, you will need to remove the rubber jounce bumpers from their cups, they will squish completely into the cup under a hard hit.

If you find that the shock has 1-2" of shaft exposed while the suspension is fully compressed, you will likely need a longer shock.

This is probably the closest you can get without having the body on to check for tire clearance
 
Can you measure the length of the spring as installed?
Your springs should be 11” (8” stock plus 3” lift) when loaded with an average weight Jeep. Anything beyond that is probably due to the springs not having a normal load.
 
Lou said:
You don’t measure shock and spring lengths when the body isn’t on the jeep...
Click to expand...
I am recommending you measure them without the body...

If you know how long the springs are right now you can estimate how much they’ll compress once you put the body back on. You know they should be about 11” when normally loaded, so if, for example, they measure 15” end to end right now, then you can estimate they’ll compress about 4” when the body is reinstalled, or you’d have 4” of shock down travel, which would be acceptable. If you get 3” or less, then your shocks are likely too short.

Not an exact method, but it’ll get you a good idea if you’re in the ballpark or not
 
You need to know the normal ride height before you can start figuring out what length shocks are the best fit. That requires the weight of the body and everything else that will be stacked on the frame.
 
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